However, I admit that although I am aware of a distinction between art nouveau and art deco, I could not give you a list of 3 things that would separate one from the other (in architectural terms). Any pointers to get us started?
I believe its to do with straight lines/angular sections - deco- as opposed to curves- nouveau. Also the period in addition to style ie nouveau from early 1900's up to late 20's. Deco style is more varied according to location, ie modernism in US, de stijl in Netherlands, etc. Not a comprehensive assessment but a start.